Immune Checkpoint Inhibitors Combined With Chemotherapy Improve Pathological Complete Response in TNBCImmunotherapy Combined With Chemotherapy Shows Higher Response Rates in TNBC

Frontiers in Medicine Published September 25, 2026 DOI ↗ Editorial oversight: Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

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Key Takeaway

Combination therapy improves pCR rates in TNBC but increases the risk of severe adverse events and treatment discontinuation.

This meta-analysis evaluated the efficacy of combining immune checkpoint inhibitors with chemotherapy for patients with early-stage or high-risk triple-negative breast cancer (TNBC). The analysis focused on pathological complete response (pCR) as the primary endpoint, comparing the combination therapy against standard control regimens.

Results indicated a statistically significant increase in pCR rates for the combination group compared to controls. This trend was consistent across various subgroups, including PD-L1-positive patients and those with node-positive disease. While the study noted high heterogeneity, the overall data suggests a measurable clinical benefit in achieving pCR.

Safety profiles revealed that the combination therapy was associated with a higher risk of grade 3-4 adverse events and serious adverse events. Additionally, there was a notable increase in treatment discontinuation rates due to toxicity. Clinicians must weigh these increased risks against the improved pathological response rates when managing TNBC patients.

How this fits prior evidence

This meta-analysis addresses a gap in the management of early-stage or high-risk triple-negative breast cancer by evaluating the efficacy of combined chemoimmunotherapy. While previous evidence has identified specific risks such as tumor necrosis-related fever during neoadjuvant chemoimmunotherapy for metaplastic breast carcinoma, this study provides specific data on pCR rates and associated toxicity for the TNBC population. The findings confirm that while immunotherapy plus chemotherapy improves pCR rates, it is associated with a higher risk of serious adverse events and treatment discontinuation.

A meta-analysis of five clinical trials looked at patients with early-stage or high-risk triple-negative breast cancer (TNBC). Researchers compared a treatment plan of immunotherapy combined with chemotherapy against standard control regimens. The study focused on the pathological complete response (pCR), which is a measure of how well the tumor responds to treatment.

The results showed that patients receiving the combination of immunotherapy and chemotherapy had higher pCR rates than those on control regimens. This trend was observed across several groups, including patients with PD-L1 positive or negative status and those with node-positive or node-negative disease. However, the researchers noted that the specific findings for PD-L1 and nodal status are exploratory.

While the combination showed higher response rates, it also came with more risks. Patients receiving the combined treatment had a higher risk of serious adverse events and a higher risk of stopping treatment early due to side effects. Because of high variability in the data and the need for more long-term evidence, these results should be viewed as a starting point for clinical discussion rather than a definitive rule.

What this means for you:

Combining immunotherapy and chemotherapy may improve response rates in TNBC but increases the risk of serious side effects.

Common questions

Does adding immunotherapy to chemotherapy help triple-negative breast cancer?

The study found that patients with early-stage or high-risk triple-negative breast cancer who received immunotherapy plus chemotherapy had higher pathological complete response (pCR) rates than those on control regimens. This suggests the combination may be more effective at shrinking tumors than chemotherapy alone.

What are the risks of this combined treatment?

The combination of immunotherapy and chemotherapy was associated with a higher risk of serious adverse events and a higher risk of treatment discontinuation due to side effects. Patients receiving this combination were more likely to experience grade 3-4 adverse events compared to those on control regimens.

Is this treatment effective for all types of triple-negative breast cancer?

The study showed higher pCR rates for both PD-L1-positive and PD-L1-negative patients, as well as for both node-positive and node-negative disease. However, these specific subgroup findings are considered exploratory, and more evidence is needed to confirm long-term outcomes.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedSep 2026

View Original Abstract ↓

BackgroundImmune checkpoint inhibitors combined with chemotherapy have improved pathological responses in early-stage triple-negative breast cancer (TNBC), but the magnitude of benefit and associated toxicity remain variable across trials. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of immunotherapy plus chemotherapy in patients with early-stage or high-risk TNBC.MethodsThis study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Embase, Web of Science, and the Cochrane Library were searched from inception to March 2026 for randomized controlled trials (RCTs). The primary outcome was pathological complete response (pCR). Dichotomous outcomes were pooled as risk ratios (RRs) with 95% confidence intervals (CIs). Between-study heterogeneity was assessed using Cochran’s Q test and the I² statistic. Exploratory subgroup analyses were conducted according to programmed death-ligand 1 (PD-L1) expression and lymph node status.ResultsFive RCTs were included. Immunotherapy plus chemotherapy was associated with a higher pCR rate than control regimens (RR = 1.44, 95% CI 1.09–1.79), with substantial heterogeneity (I² = 83.7%). In exploratory analyses, the pooled RR was 1.36 (95% CI 1.18–1.57) in PD-L1-positive patients and 1.18 (95% CI 0.96–1.45) in PD-L1-negative patients. Corresponding RRs were 1.42 (95% CI 1.19–1.69) for node-positive and 1.21 (95% CI 1.02–1.43) for node-negative disease. Immunotherapy-containing regimens were also associated with higher risks of grade 3–4 adverse events (RR = 1.18, 95% CI 1.05–1.33), serious adverse events (RR = 1.42, 95% CI 1.12–1.79), and treatment discontinuation due to adverse events (RR = 1.67, 95% CI 1.18–2.36).ConclusionsImmunotherapy combined with chemotherapy was associated with higher pCR rates in early-stage or high-risk TNBC but also with greater treatment-related toxicity. PD-L1 and nodal subgroup findings should be considered exploratory, and further evidence is needed to clarify long-term clinical outcomes.Systematic review registration[url], identifier [].

Immune Checkpoint Inhibitors Combined With Chemotherapy Improve Pathological Complete Response in TNBCImmunotherapy Combined With Chemotherapy Shows Higher Response Rates in TNBC

How this fits prior evidence

Common questions

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Immune Checkpoint Inhibitors Combined With Chemotherapy Improve Pathological Complete Response in TNBCImmunotherapy Combined With Chemotherapy Shows Higher Response Rates in TNBC

How this fits prior evidence

Common questions

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